The present invention relates to an exhaust hood and more particularly to an exhaust hood having a reduced noise level for use with a cooking appliance.
Exhaust hoods are used in a wide variety of environments including in kitchens to exhaust or filter cooking vapors and fumes, bathrooms, laboratories and other environments where various gases and vapors need to be exhausted from an enclosed space, or treated or filtered and returned to the enclosed space.
Typically the exhaust hoods include some type of air moving device, generally a fan or blower. Preferably the fan or blower will be sufficiently large so as to provide a desired rate of air flow through the hood in order to provide the desired level of exhausting or treating of the air within the enclosed space. However, oftentimes the operation of the air moving device, particularly at higher levels of air movement, creates a noise level which may range from irritating to disruptive.
Attempts have been made in the past to provide exhaust hoods with various features to reduce the noise level produced by operating the exhaust hood. For example, U.S. Pat. No. 5,720,274 discloses a vapor exhaust hood which includes sound absorbing material on various surfaces within the exhaust hood and an elastic mounting of the fan and/or fan motor.
U.S. Pat. No. 5,326,317 discloses an exhaust blower having a "soundproof" unit on the inlet side of the blower to reduce the level of noise generated by the blower which would otherwise be transmitted through the inlet.
U.S. Pat. No. 4,877,106 discloses a noise attenuating assembly arranged at an exhaust opening of an air conditioner to deflect and absorb line-of-sight sound produced by the air conditioner fan.
U.S. Pat. No. 3,452,677 discloses the use of a baffle and various sound absorbing materials within an air outlet passage from an air conditioning system.
U.S. Pat. Nos. 4,330,047 and 2,704,504 disclose various sound-attenuating louvers and air passages to be used in conjunction with air flow from one space to another.